vhangup(2)

NAME

     vhangup - virtually "hangup" the current controlling  termi-
     nal

SYNOPSIS

     #include <unistd.h>

     void vhangup(void);

DESCRIPTION

     The vhangup() function is used by the initialization process
     init(1M)  (among  others)  to  ensure  that  users are given
     "clean" terminals at login by revoking access of the  previ-
     ous  users'  processes  to  the  terminal.  To  effect this,
     vhangup() searches the system tables for references  to  the
     controlling  terminal  of  the  invoking process and revokes
     access permissions on each instance of the terminal that  it
     finds.  Further  attempts  to  access  the  terminal  by the
     affected processes will yield I/O errors (EBADF or  EIO).  A
     SIGHUP  (hangup  signal) is sent to the process group of the
     controlling terminal.

SEE ALSO

     init(1M)

BUGS

     Access to the controlling terminal using /dev/tty  is  still
     possible.

     This call should be replaced by an automatic mechanism  that
     takes place on process exit.